1. Field of the Invention
The invention relates to a power plug, more particularly to a car power plug that is insertable into a car cigarette lighter socket.
2. Description of the Related Art
Cars are generally provided with a cigarette lighter. The cigarette lighter has a socket body and a plug provided with an electric heating element. When the plug is inserted into the socket body and is pressed inward, the heating element of the plug will be electrically connected to the socket body and becomes heated instantly. A user can then take out the plug and use the heating element to light a cigarette.
In order to better utilize the power supplied via the cigarette lighter socket, a power plug for electrical connection to the cigarette lighter socket to obtain supply of electric power has been developed. Moreover, in order to match the shape of the cigarette lighter socket, a conventional power plug is configured to have a cylindrical structure. FIG. 1 shows a power plug 9 disclosed in R.O.C. Utility Model No. 95200092, which has two conductive pieces 91 provided respectively on two diametrically opposite sides thereof for electrical connection with negative power terminals in a car cigarette lighter socket (not shown), and a conductive block 92 projecting from a front end thereof for electrical connection with a positive power terminal in the cigarette lighter socket. Power plugs for cars as disclosed in R.O.C. Utility Model Nos. 94212951, 91206155 and 90204504 are also cylindrical plugs.
Since the size of such a power plug 9 is relatively large, if the power plug 9 is to be integrated with an electronic device or configured to be foldably accommodated in an electronic device, the overall size of the electronic device will be inevitably increased in order to provide a sufficient space for accommodating the power plug 9. Thus, miniaturization of modern electronic equipment that is desired to be compact cannot be effectively achieved.